There are more sexual assault allegations against a former Michigan State team doctor.

Twenty-three new charges of sexual assault against Larry Nassar were filed Wednesday, according to the Lansing State Journal. The charges are the latest against Nassar, who is the subject of an investigation that started last fall. Nassar worked closely with the Spartans’ women’s gymnastics team among other teams at the school.

From the Lansing State Journal:

The 23 charges of first-degree criminal sexual conduct relate to six different alleged victims, according to testimony today. The alleged assaults occurred during medical appointments that include procedures that included digital, vaginal and anal penetration, according to testimony.

Many of the women were minors at the time of the alleged assaults.

Nassar was fired by Michigan State in September after nearly two decades with the school’s athletic department. He was first charged in November on three counts of first-degree sexual assault, according to the Lansing State Journal.

There have also been allegations that women’s gymnastics coach Kathie Klages ignored athletes’ complaints about Nassar’s alleged assaults. Klages announced her retirement last week after she was suspended by the school.